print("Hello World") x <- seq(1,10,by=0.1) y <- x*x plot(x, y, type="l") print(class(x)) print(3 < 4) print(3 < 3) print(3 <= 3) print(9 / 4) print(9 %% 4) print(10 %% 5) print(2 ^ 3) print(2 ** 3) x <- 2**3 class(x) x <- "3.14" print(as.numeric(x) + 1) x <- 1 / 0 print(x) sentence <- "Jeff's brother's name is Kevin. Jeff says \"yes\"" print(x/x) class(x/x) x <- 10:15 print(x[1]) x <- matrix(c(1,2,3,4), nrow=2, ncol=2, byrow=TRUE) View(x) print(x[1, 2]) x <- array(c(1,2,3,4), dim=c(10,10)) View(x) print(x[1,]) print(x[1:5,10]) y <- x[,1] >= 3 y x[y,] c(1,2,3,4) + c(2,3) x <- data.frame(name=c("Jeff", "Devon", "Sarah"), age=c(42, 42, 3.14), gender=as.factor(c("male", "female", "female"))) View(x) x[2,1] x[,2] x$age hello <- function() { print("Hello World!") print("And good bye:(") 42 # if no return statement, then the last expression is the return value } x <- hello() stuff <- function(x1, x2, x3) { print(x1) print(x2) print(x3) print(min(c(x1,x2,x3))) print(max(c(x1,x2,x3))) print(mean(c(x1,x2,x3))) return(c(x1,x2,x3)) # last statement of the function print("hi") # this doesn't print } # goal, call it like result <- stuff(1,2,3) # print max, min, mean # the following would be an error, x1 doesn't exist out here #print(x1) isPrime <- function(n) { # assume everything is okay for(i in 2:(n-1)) { #print(i) if (n %% i == 0) { return(FALSE) } } return(TRUE) } print(isPrime(2013))